During medical treatment, patients often require medication, blood, and fluids. The most efficient way of administering these substances is by depositing them directly into the patient's blood stream where the circulatory system quickly directs the substance to the target tissue or organ. Administering a substance directly into a patient's blood stream is most commonly accomplished by injection with a conventional needle and syringe. During the course of treatment, however, a patient will often require repeated or continuous doses of medications. It will be appreciated that repeated injections with conventional syringes can damage blood vessels and cause significant discomfort to the patient.
Therefore, when a patient requires repeated doses of medication or other substances, catheters are commonly used in the health care profession. In one common configuration, a catheter comprises a catheter adaptor and a hollow tubular cannula. The catheter adaptor and cannula are usually constructed from a single mold such that a continuous fluid passage extends from the catheter adaptor to the catheter cannula. When the catheter is in use, the hollow tubular cannula is disposed within the patient's blood vessel, while the catheter adaptor remains outside where it can be accessed by medical personnel. A medication, blood, or fluid container is securely attached to the catheter adaptor. The substance in the container flows through the continuous fluid passage in the catheter and directly into the patient's blood vessel. As such, the patient receives a continuous supply of medication, blood, or fluid without repeated injections with conventional needles and syringes.
Typically, a vascular access device is used to insert a catheter within a patient's blood vessel. A vascular access device generally comprises a needle puller, an introducer needle, and a catheter. The needle puller is used to grip the vascular access device during catheter insertion. The sharp introducer needle having a beveled tip is attached to the end of the needle puller and used to pierce the patient's skin and access the patient's blood vessel. The catheter concentrically fits over the introducer needle through the continuous fluid passage in the catheter and is held in place by friction engagement between the catheter adaptor and the needle puller. The catheter is usually constructed of a pliable material that will not irritate the inner wall of the blood vessel or unduly limit the patient's movement.
The introducer needle is longer than the catheter cannula. Therefore, when the catheter adaptor is properly attached to the needle puller, the beveled tip of the introducer needle extends beyond the end of catheter cannula. It is important that the introducer needle extend beyond the catheter cannula so that during catheter insertion the introducer needle is available to pierce the patient's skin and access the blood vessel. It will be appreciated that because the catheter is made of a pliable material, unless the introducer needle first pierces the patient's skin and blood vessel, the catheter cannula cannot be inserted into the patient's blood vessel.
In use, a clinician, while gripping the needle puller, pierces the patient's skin with the introducer needle and locates the patient's blood vessel. Once the introducer needle is in the patient's blood vessel, the clinician detaches the catheter adaptor from the needle puller. The catheter cannula is then inserted into the patient's blood vessel by sliding it along the introducer needle until the desired length of the cannula is within the blood vessel. Once the catheter cannula is in place, the introducer needle is removed by slowing pulling back on the needle puller, leaving the catheter cannula within the patient's blood vessel. Finally, a medication, blood, or fluid container is attached to the catheter adaptor.
It will be appreciated, however, that for a variety of reasons it is often difficult to locate and successfully insert the introducer needle into the blood vessel of interest. When the blood vessel is small or difficult to locate, clinicians tend to hold the vascular access device by the catheter adaptor rather than the needle puller. Like a baseball player choking on a bat, holding the vascular access device nearer the tip of the introducer needle gives the clinician greater stability and control over the introducer needle. The increased stability and control makes it easier to insert the introducer needle and catheter cannula into the patient's blood vessel.
Unfortunately, conventional vascular access devices do not permit the clinician to grip the vascular access device by the catheter adaptor. Initially, the catheter adaptor is securely attached to the needle puller by friction engagement. The force used to pierce the patient's skin, however, often causes the catheter adaptor to uncouple from the needle puller before the blood vessel has been located and pierced. Once the catheter is uncoupled, the catheter cannula prematurely slides along the introducer needle. The introducer needle, therefore, cannot be advanced further, making it difficult, if not impossible, to insert the pliable catheter cannula into the patient's blood vessel.
From the foregoing, it will be appreciated that it would be an advancement in the art to provide a device that would permit a vascular access device to be gripped by the catheter adaptor. It would be yet another advancement to provide a device for coupling a needle puller to a catheter such that the catheter does not prematurely uncouple from the needle puller during catheter insertion. It would be a further advancement in the art if the coupling device could be easily disengaged once the introducer needle was in the blood vessel and the catheter was ready for insertion into the patient's blood vessel. In would be yet another advancement if the coupling device could be disengaged with one hand. Such a coupling device is disclosed and claimed herein.